Silent Super Efficient Propeller!

a wrote in
:

On Sep 6, 3:51*am, Bertie the Bunyip wrote:
a wrote in
news:e5fb9dcd-6bd8-42e3-9a50-f6370d188424
@x35g2000hsb.googlegroups.com:

On Sep 5, 6:46*pm, Leviterande Leviterande.
wrote:
Now woludnt a shorter prop with a bigger chord(and q-tips) move
more a
ir
and thus creating equal thrust as a longer propeller with thinner
chor
d?

when I tried the patented fan it was pretty quiet *however.

How did you try the patented fan?

AS for longer chords? Probably not. Think of the *most efficient
wing
s
for airplanes -- the ones that provide the best lift/drag. They are
long and slender. The same principles hold for props. You can be
sure if wide chords were better they'd be showing up on
experimental aircraft, and they are not.

They do actually, and they can be very efficient indeed.

http://www.youtube.com/watch?v=Nxz1UF67EQI

There's also been the Dyke Delta, and the facetmobile, of course.

Bertie

I don't think you'd find these as 'efficient' as conventionally shaped
aircraft, else we'd be seeing competition gliders shaped this way.
Those airplane shapes would have very light wing loading of course,
but huge wetted areas -- think drag.


Yeah, I understand al of that, but the word efficient is one that is
often bandied as some sort of standard, but is just as misunderstood.

While I know you mean aerodynamic efficiency in it's purest form, the
mission is the yardstick by which you must measure the success of an
airplane. Gliders are good at what they do, but they're as much a
compromise as any other type of airplane. Low aspect ration machines
have a few enormous advantages, not the least of which is a huge speed
range and relatively low drag at low alpha. Span loading is more
relevant than area loading in many ways and application, depending on
what you're trying to get the wing to do at any given momen, and a low
span loading, as in a glider, has to be paid for with drag just like
any other aerodynamic benifit. Simply put, the longer the span, the more
air you're moving around. Now, for some applications, this is more
efficient, since by agitating a greater volume air in a less agressive
fashion than a little air, you may, and may is the operative word here,
create less drag in your flight situation.

. As for using that concept for prop blade shape, , where efficiency
is defined in the conventional engineering sense as power out divided
by power in, long and thin blades seem to win over short and fat.

Depends on the application and what you're asking the blade to do.
Length brings its own problem here again, but in spades, since tip
speeds, particulalry at high cruise speeds, becomes a problem.
There simply are no pat answers in aerodynamics. "Monoplanes are more
efficient than biplanes" for instnace, is an oft touted example. Simply
not true in every aspect. It depends on what you're asking the airplane
to do. Of course, particualrexamples may be plucked from the air to
prove almost any POV here. You could look at two types of aircraft and
compare their performance with a single yardstick, such as fuel burn,
but that doesn't make one more efficient than another as whole. just on
fuel burn. If the fuel efficient one can't get out of the 800 foot strip
it's parked in and the other one can, then the one that can is the more
efficient machine for it's mission. That's not to say some airplanes
aren't just plain inefficient, but it is a bit ridiculous to say that
just because there's a popular mission and most airplanes tend to gel in
that corner of design that those types of aircraft are ultimatley the
most efficient things in the sky.



Bertie

On Sep 6, 5:41*am, Bertie the Bunyip wrote:
a wrote :



On Sep 6, 3:51*am, Bertie the Bunyip wrote:
a wrote in
news:e5fb9dcd-6bd8-42e3-9a50-f6370d188424
@x35g2000hsb.googlegroups.com:

On Sep 5, 6:46*pm, Leviterande Leviterande.
wrote:
Now woludnt a shorter prop with a bigger chord(and q-tips) move
more a
ir
and thus creating equal thrust as a longer propeller with thinner
chor
d?

when I tried the patented fan it was pretty quiet *however.

How did you try the patented fan?

AS for longer chords? Probably not. Think of the *most efficient
wing
s
for airplanes -- the ones that provide the best lift/drag. They are
long and slender. The same principles hold for props. You can be
sure if wide chords were better they'd be showing up on
experimental aircraft, and they are not.

They do actually, and they can be very efficient indeed.

http://www.youtube.com/watch?v=Nxz1UF67EQI

There's also been the Dyke Delta, and the facetmobile, of course.

Bertie

I don't think you'd find these as 'efficient' as conventionally shaped
aircraft, else we'd be seeing competition gliders shaped this way.
Those airplane shapes would have very light wing loading of course,
but huge wetted areas -- think drag.

Yeah, I understand al of that, but the word efficient is one that is
often bandied as some sort of standard, but is just as misunderstood.

While I know you mean aerodynamic efficiency in it's purest form, the
mission is the yardstick by which you must measure the success of an
airplane. Gliders are good at what they do, but they're as much a
compromise as any other type of airplane. Low aspect ration machines
have a few enormous advantages, not the least of which is a huge speed
range and relatively low drag at low alpha. Span loading is more
relevant than area loading in many ways and application, depending on
what you're trying to get the wing to do at any given momen, and a low
span loading, as in a glider, has to be paid for with *drag just like
any other aerodynamic benifit. Simply put, the longer the span, the more
air you're moving around. Now, for some applications, this is more
efficient, since by agitating a greater volume air in a less agressive
fashion than a little air, you may, and may is the operative word here,
create less drag in your flight situation.

. As for using that concept for prop blade shape, , where efficiency
is defined in the conventional engineering sense as power out divided
by power in, long and thin blades seem to win over short and fat.

Depends on the application and what you're asking the blade to do.
Length brings its own problem here again, but in spades, since tip
speeds, particulalry at high cruise speeds, becomes a problem.
There simply are no pat answers in aerodynamics. "Monoplanes are more
efficient than biplanes" for instnace, is an oft touted example. Simply
not true in every aspect. It depends on what you're asking the airplane
to do. Of course, particualrexamples may be plucked from the air to
prove almost any POV here. You could look at two types of aircraft and
compare their performance with a single yardstick, such as fuel burn,
but that doesn't make one more efficient than another as whole. just on
fuel burn. If the fuel efficient one can't get out of the 800 foot strip
it's parked in and the other one can, then the one that can is the more
efficient machine for it's mission. That's not to say some airplanes
aren't just plain inefficient, but it is a bit ridiculous to say that
just because there's a popular mission and most airplanes tend to gel in
that corner of design that those types of aircraft are ultimatley the
most efficient things in the sky.

Bertie

The mission that seems best served by short span broad chord
propellers seems to be in the marinas -- long and thin are not popular
there. Even that may be changing, you may have seen a satellite view
of an Ohio class submarine with its screw exposed recently (the navy
goofed, those things are usually shrouded when they would be otherwise
exposed) and it looked like something that belonged on an airplane.

See

http://www.armscontrolwonk.com/1626/secret-screws

Bertie, yes sad all available science arnt known nor popular among people, circular wing and flying wings that are chord thick proved to be alot better then just rektangular slender wings, the stall speed is very very low, the weight strength ratio is awsome .. etc..

the model of the propeller I made was alot quiter then normal propellers.. but it was way out of balance and so i didnt get thrust enough.. I just made it with foam)depron)

On Sat, 6 Sep 2008 05:33:08 +0100, Leviterande wrote in
:

does anybody have a good pic of a Q-tip propeller?

This might be one:

http://www.princeaircraft.com/PhotoGallery.aspx?id=83

it seems hard to find any...

Agreed!

Here's a good one. You can zoom in on the picture and
see the Q-tips quite clearly:

http://www.controller.com/listings/aircraft-for-sale/PIPER-NAVAJO-CHIEFTAIN-PANTHER/1979-PIPER-NAVAJO-CHIEFTAIN-PANTHER/1141689.htm?guid=69E298042EB54588BA0A2765C1D8FC02& dlr=1

Marty
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"Bertie the Bunyip" wrote in message
...

Power/mercy snip -

Bertie


What a load of bull****.

Efficiency is directly related to mission profile. That's not a spin, is
frigging verbal lomcevak.

If I didn't know better, I would suspect Anthony was forging your post.

"Bertie the Bunyip" wrote in message
...


They do actually, and they can be very efficient indeed.


http://www.youtube.com/watch?v=Nxz1UF67EQI

There's also been the Dyke Delta, and the facetmobile, of course.



Bertie


Why would the Buttlipps be promoting the flying HEEL?

Professional courtesy?
Kindred spirit?
Name association?

Actually in teh begining of the last century many designers started building circular aircraft, and all teh reports indicated that the flying saucer had advantages as :

easy and slow to fly

almost impossible to stall

highly crash proof

cheap easy to manufacter

if you dont think that is efficieny then I dont know what it is

i read also in leonard G cramps books that during early wing tunnel tests
the standard wing were ""retricted to be tested with very limited AOA"" unlike the circular wings taht have been tested in extreme angles of attack without stall!!


well, it is been a little offtopic but lets take a look at this propeller I found and it is patented 2008

it is easy to contruct too

what do you think?

http://www.freepatentsonline.com/7396208.html
http://www.linkgrinder.com/Patents/D...r_7396208.html

Originally Posted by Lonnie[_3_]

"Bertie the Bunyip" wrote in message
...


They do actually, and they can be very efficient indeed.


http://www.youtube.com/watch?v=Nxz1UF67EQI

There's also been the Dyke Delta, and the facetmobile, of course.



Bertie


Why would the Buttlipps be promoting the flying HEEL?

Professional courtesy?
Kindred spirit?
Name association?

On Sep 6, 7:03*am, Leviterande Leviterande.
wrote:
Bertie, yes sad all available science arnt known nor popular among
people, *circular wing and flying wings that are chord thick proved to
be alot better then just rektangular slender wings, the stall speed is
very very *low, the weight strength ratio is awsome .. etc..

the model of the propeller I made was alot quiter then normal
propellers.. but it was way out of balance and so i didnt get thrust
enough.. I just made it with foam)depron)

--
Leviterande

I'm really interested in how you determined those noise
characteristics with a prop made of structural foam. Did you have an
internal structure for strength? And as for noise, were you comparing
it to a conventional prop made the same way? I'd like to know how to
model some things like this myself, would rather learn from someone
else's experience than have to reinvent something.

On Sep 6, 11:15*am, Leviterande Leviterande.
wrote:
Actually in teh begining of the * last century many designers started
building circular aircraft, and all teh reports indicated that the
flying *saucer had advantages as :

easy and slow to fly

almost impossible to stall

highly crash proof

cheap easy to manufacter

if you dont think that is efficieny then I dont know what it is

i read also in leonard G cramps books that during early wing tunnel
tests
the standard wing were *""retricted to be tested with * very limited
AOA"" unlike the circular wings taht have been tested in extreme angles
of attack without stall!!

well, it is been a little offtopic but lets take a look at this
propeller I found and it is patented 2008

it is easy to *contruct too

what do you think?

http://www.freepatentsonline.com/739...r_7396208.html

'Lonnie[_3_ Wrote:



;659369']"Bertie the Bunyip" wrote in message
.. .-

They do actually, and they can be very efficient indeed.

http://www.youtube.com/watch?v=Nxz1UF67EQI

There's also been the Dyke Delta, and the facetmobile, of course.

Bertie
-

Why would the Buttlipps be promoting the flying HEEL?

Professional courtesy?
Kindred spirit?
Name association?

--
Leviterande

"Efficiency" in the sense I am using it is in the conventional
engineering terms -- power out divided by power in. For every
horsepower you deliver to the prop shaft under given conditions there
some work -- force times distance -- returned. It's perfectly fine to
use different definitions, but let the reader know what the definition
is.

I've the sense one can get even higher than the 75 to 80 percent good
ones deliver these days, but the 'overhead' in ducts and the like make
those systems not quite realizable: that is, practical, for general
aviation. Be interesting to see what happens..

a wrote in
:

On Sep 6, 5:41*am, Bertie the Bunyip wrote:
a wrote
innews:14d9aabc-33a9-4fdf-9ca5-78e407249a02@7
9g2000hsk.googlegroups.com:



On Sep 6, 3:51*am, Bertie the Bunyip wrote:
a wrote in
news:e5fb9dcd-6bd8-42e3-9a50-f6370d188424
@x35g2000hsb.googlegroups.com:

On Sep 5, 6:46*pm, Leviterande Leviterande.
wrote:
Now woludnt a shorter prop with a bigger chord(and q-tips) move
more a
ir
and thus creating equal thrust as a longer propeller with
thinner chor
d?

when I tried the patented fan it was pretty quiet *however.

How did you try the patented fan?

AS for longer chords? Probably not. Think of the *most efficient
wing
s
for airplanes -- the ones that provide the best lift/drag. They
are long and slender. The same principles hold for props. You
can be sure if wide chords were better they'd be showing up on
experimental aircraft, and they are not.

They do actually, and they can be very efficient indeed.

http://www.youtube.com/watch?v=Nxz1UF67EQI

There's also been the Dyke Delta, and the facetmobile, of course.

Bertie

I don't think you'd find these as 'efficient' as conventionally
shaped aircraft, else we'd be seeing competition gliders shaped
this way. Those airplane shapes would have very light wing loading
of course, but huge wetted areas -- think drag.

Yeah, I understand al of that, but the word efficient is one that is
often bandied as some sort of standard, but is just as misunderstood.

While I know you mean aerodynamic efficiency in it's purest form, the
mission is the yardstick by which you must measure the success of an
airplane. Gliders are good at what they do, but they're as much a
compromise as any other type of airplane. Low aspect ration machines
have a few enormous advantages, not the least of which is a huge
speed range and relatively low drag at low alpha. Span loading is
more relevant than area loading in many ways and application,
depending on what you're trying to get the wing to do at any given
momen, and a low span loading, as in a glider, has to be paid for
with *drag just like any other aerodynamic benifit. Simply put, the
longer the span, the more air you're moving around. Now, for some
applications, this is more efficient, since by agitating a greater
volume air in a less agressive fashion than a little air, you may,
and may is the operative word here, create less drag in your flight
situation.

. As for using that concept for prop blade shape, , where
efficiency is defined in the conventional engineering sense as
power out divided by power in, long and thin blades seem to win
over short and fat.

Depends on the application and what you're asking the blade to do.
Length brings its own problem here again, but in spades, since tip
speeds, particulalry at high cruise speeds, becomes a problem.
There simply are no pat answers in aerodynamics. "Monoplanes are more
efficient than biplanes" for instnace, is an oft touted example.
Simply not true in every aspect. It depends on what you're asking the
airplane to do. Of course, particualrexamples may be plucked from the
air to prove almost any POV here. You could look at two types of
aircraft and compare their performance with a single yardstick, such
as fuel burn, but that doesn't make one more efficient than another
as whole. just on fuel burn. If the fuel efficient one can't get out
of the 800 foot strip it's parked in and the other one can, then the
one that can is the more efficient machine for it's mission. That's
not to say some airplanes aren't just plain inefficient, but it is a
bit ridiculous to say that just because there's a popular mission and
most airplanes tend to gel in that corner of design that those types
of aircraft are ultimatley the most efficient things in the sky.

Bertie

The mission that seems best served by short span broad chord
propellers seems to be in the marinas -- long and thin are not popular
there. Even that may be changing, you may have seen a satellite view
of an Ohio class submarine with its screw exposed recently (the navy
goofed, those things are usually shrouded when they would be otherwise
exposed) and it looked like something that belonged on an airplane.

Well, my main drive has short span long chord blades. So do most high
bypass fan jets...

Bertie